ALL ABOARD The Polar Pattern Express! Not the movie. 😁
Today, we will explore microphone polar patterns and examine specific applications suited to microphones with various polar pattern types.
What Is A Polar Pattern?
Each microphone has a polar, or pickup, pattern, and it’s essential to understand the specific polar patterns used by our microphones. But what exactly is a polar pattern, and why is it important?
A polar pattern defines how a microphone captures sound, specifically indicating the microphone’s sensitivity to sound waves arriving from various directions. There are several polar patterns, but I will focus on the four patterns you are most likely to encounter on a live sound stage.
Omnidirectional Polar Pattern
The first is polar pattern is omnidirectional. This mic pattern picks up sound in a 360° sphere around the microphone capsule—all directions equally. While this pattern can be useful in some live sound applications, be careful! Omni mics can be very susceptible to feedback because they pick up sound from all directions—front, back, up, down, etc. In a live sound situation omni directional mics work best when placed in close proximity to the sound source.
This photo shows a few examples of omni directional mics that are commonly used in the house of worship application.
Omnidirectional microphones are excellent for capturing the overall atmosphere of a venue. At a church where I previously worked, the space had a large audience area but relatively low ceilings in the wings of the meeting space. To capture audience reactions for our live radio and livestream broadcasts, we suspended omnidirectional lavalier microphones throughout the seating area. These served effectively as ambient mics, allowing us to enhance the broadcast with real-time audience responses.
Another commonly used omni directional mic is this pencil style condenser. You may see this being used for drum overheads, high hat, grand pianos or for miking a choir or an orchestral string section.
There are a number of pastors that prefer the lavaliere or lapel microphone because it’s inconspicuous and looks good on video. Most of these are omnidirectional and quite difficult to get much gain before feedback because this mic is placed so far away from the sound source (or mouth) giving it a less than optimal signal to noise ratio.
A more stable omni directional mic for the spoken word is the over the ear headset. Because it’s placed very close to the mouth, one can achieve quite a bit more gain before feedback.
The Cardioid Polar Pattern
The next polar pattern is Cardioid. This pattern looks a little bit like a heart, hence the name cardioid. Cardioid microphones are highly popular in live sound settings due to their directional pickup pattern, which captures sound primarily from the front while rejecting noise from the sides and rear.
Here are some of the most common uses:
Vocals: Cardioid mics are often used for vocalists on stage because they help isolate the singer’s voice from other sounds, reducing feedback and background noise.
Instruments: They are frequently used to mic up instruments like guitar amps, drums, and keyboards, ensuring that the sound is focused and clear.
Speech and Presentations: These mics are also ideal for speeches and presentations, as they can effectively capture the speaker’s voice while minimizing ambient noise.
I find it fascinating that the Shure SM58 and SM57 cardioid microphones have been a staple in the music industry since the mid 1960’s and continue to be a popular choice for vocalists and instrumentalists around the world delivering quality sound and durability at an affordable price point. When newcomers to the audio world ask for advice on purchasing their first cardioid vocal and instrument microphones, I consistently recommend starting with the Shure SM57s and SM58s.
Super-Cardioid and Hyper-Cardioid Polar Patterns
These next 2 polar patterns are worth mentioning together because they look very much alike.
The super-cardioid pattern is very similar to a Cardioid pattern but features a narrower pickup pattern in front of the microphone, rejecting more sound from the sides of the mic. However, there is a larger rear lobe in the back of the mic that can be slightly more susceptible to sound coming from directly behind the mic.
Super-cardioid are great for live performances, especially in noisy environments, as they help isolate the main sound source and reduce feedback.
A hyper-cardioid mic will have an even more narrow coverage pattern than the super-cardioid. There is also a slightly larger rear lobe that will pick up sound from behind the mic.
“Shotgun” mics often use this type of pattern for the enhanced directional control that can be achieved when aiming the mic at the specific sound source. This can be super advantageous for a vocalist until they move off to the side of the mic. At that point their vocal will all but disappear.
The hyper-cardioid shotgun microphone is an excellent choice for capturing audience sound during live event broadcasts, such as concerts or church services. When properly aimed at the audience, its polar pattern minimizes the pickup of sound from the main house loudspeakers, ensuring clarity of the audience reactions.
In concerts or theater productions, hyper-cardioid mics minimize bleed from other instruments and stage noise, ensuring clear sound capture.
Understanding Microphone Polar Patterns and Stage Monitor Placement
Proper floor monitor placement in relation to a microphone’s polar pattern is crucial to minimize feedback and ensure clear sound.
Here are some best practices for monitor placement when using a cardioid microphone.
Position Directly Behind the Microphone: Since cardioid microphones are least sensitive at the rear, place the monitor directly behind the microphone. This helps to avoid picking up sound from the monitor.
Maintain Distance: Keep a distance of about 3 to 5 feet between the monitor and the microphone stand. This distance helps to prevent feedback and allows the performer to move freely.
Angle the Monitor: Tilt the monitor slightly upwards towards the performer’s ears. This ensures that the sound is directed towards the performer and not towards the microphone.
Here are some best practices for monitor placement when using a super-cardioid or hyper-cardioid microphone.
Position Monitors at an Angle: Unlike cardioid mics, super and hyper cardioid mics have a narrower pickup pattern and a small lobe of sensitivity at the rear. Place the monitors at approximately 120 degrees off-axis from the front of the microphone. This means positioning the monitors slightly to the sides rather than directly behind.
Use Two Monitors: If possible, use two monitors placed on either side of the performer. This setup helps to avoid the rear lobe of sensitivity and provides better sound coverage.
Maintain Distance: Keep a distance of about 3 to 5 feet between the monitors and the microphone stand. This helps to prevent feedback and allows the performer to move freely.
Angle the Monitors Upwards: Tilt the monitors slightly upwards towards the performer’s ears. This ensures that the sound is directed towards the performer and not towards the microphone.
For omnidirectional microphones, which pick up sound equally from all directions, floor monitor placement requires careful consideration to avoid feedback and ensure clear sound. Here are some best practices:
Distance from the Microphone: Place the floor monitor at a reasonable distance from the microphone to prevent feedback. Since omnidirectional mics pick up sound from all directions, keeping the monitor further away helps reduce the risk of feedback.
Monitor Angle: Angle the monitor slightly upwards towards the performer’s ears. This ensures that the sound is directed towards the performer and not towards the microphone.
Volume Control: Keep the monitor volume at a moderate level. High volumes can increase the likelihood of feedback, especially with omnidirectional mics.
Use Multiple Monitors: If possible, use multiple monitors placed around the performer. This can help distribute the sound evenly and reduce the need for high volume levels.
Always refer to the specific polar pattern of your microphone to understand its sensitivity zones. This will help you place the monitor in the optimal position for maximum rejection of unwanted sound.
Polar Pattern Wrap Up
Knowing your microphone’s polar pattern in a live sound reinforcement scenario is essential for managing feedback, isolating specific sound sources, and capturing ambient sounds effectively. Different polar patterns offer unique advantages in controlling unwanted noise and enhancing sound quality. This knowledge allows sound engineers to select the right microphone for each application, ensuring a clear and focused audio experience for both performers and the audience.
About the author
Golden Preciado is a Training Specialist and House of Worship Specialist for QSC, the Lead Audio Engineer at Grace Fellowship Church in Costa Mesa, CA, as well as a freelance engineer/consultant with her firm Golden Audio Mix . Golden grew up in the music industry and followed in her dad’s footsteps as an audio engineer, musician and worship leader. Golden is an accomplished front of house and broadcast engineer not only in the church world but in the secular music industry as well. She enjoys teaching her skill set to others, including online and on site where training is needed.
